Towards coherent optical control of a single hole spin: Rabi rotation of a trion conditional on the spin state of the hole

A. J. Ramsay, S. J. Boyle, T. M. Godden, R. S. Kolodka, A. F. A. Khatab, J. B. B. Oliveira, J. Skiba-Szymanska, H. -Y. Liuc, M. Hopkinson, A. M. Fox, M. S. Skolnick

Published 2009-07-27Version 1

A hole spin is a potential solid-state q-bit, that may be more robust against nuclear spin induced dephasing than an electron spin. Here we propose and demonstrate the sequential preparation, control and detection of a single hole spin trapped on a self-assembled InGaAs/GaAs quantum dot. The dot is embedded in a photodiode structure under an applied electric-field. Fast, triggered, initialization of a hole spin is achieved by creating a spin-polarized electron-hole pair with a picosecond laser pulse, and in an applied electric-field, waiting for the electron to tunnel leaving a spin-polarized hole. Detection of the hole spin with picosecond time resolution is achieved a second picosecond laser pulse to probe the positive trion transition, where a trion is created conditional on the hole spin to be detected as a change in photocurrent. Finally, using this setup we observe a Rabi rotation of the hole-trion transition that is conditional on the hole spin, which for a pulse-area of $2\pi$ can be used to impart a phase-shift of $\pi$ between the hole spin states, a non-general manipulation of the hole spin.